Blood Tests Before Pregnancy: What to Check

If you are planning a pregnancy, the months before you start trying are a good time to check your health. Some things, such as low iron, an underactive thyroid or raised blood sugar, are easier to put right before pregnancy than during it, and knowing your immunity and infection status early helps you plan with your GP.

This guide sets out the blood tests worth considering before pregnancy, the NHS supplement advice that applies to everyone, which panel to choose and what the NHS already offers once you are pregnant. A result does not predict whether or when you will conceive. It gives you and your practitioner or GP a clear starting point.

Test it in Chiswick: our Fertility Panel blood test costs £159, with your result explained in person by a practitioner. No GP referral needed. Book this test or call 020 4515 0000.

Quick answer

Useful blood tests before pregnancy include a full blood count and ferritin for iron, folate and vitamin B12, thyroid function, vitamin D, HbA1c for blood sugar, rubella immunity if you are not sure you have had two MMR doses, and an STI screen for HIV, syphilis and hepatitis B. AMH is only worth testing if you have a specific question about egg reserve. Whatever your results, the NHS advises 400 micrograms of folic acid a day, ideally from 3 months before you conceive until 12 weeks of pregnancy, and 10 micrograms of vitamin D a day.

Blood tests that can help

Rubella immunity

Rubella in pregnancy can harm a baby. Routine rubella screening in pregnancy ended in England in 2016, partly because rubella is now very rare in the UK, and the advice is to make sure you have had the MMR vaccine before trying for a baby. Your GP surgery should be able to tell you which vaccines you have had. If you are unsure, a Rubella Immunity test (£89) checks for protective antibodies, or the MMR Immunity Check (£189) covers measles, mumps and rubella. MMR is a live vaccine that is not given in pregnancy, and NHS guidance is to avoid getting pregnant for one month after it.

Folate and vitamin B12

Folic acid helps prevent neural tube defects such as spina bifida. A Folate (Folic Acid) test (£49) and a Vitamin B12 test (£49) show your current levels, which is useful if you follow a vegan diet or have a gut condition. A normal result does not replace the supplement: the NHS advises everyone trying to conceive to take 400 micrograms of folic acid daily. A higher 5mg dose on prescription is advised for some people, for example if you have diabetes, take medicine for epilepsy or HIV, or have a personal or family history of a neural tube defect. Your GP can advise.

Ferritin and full blood count

The NHS lists pregnancy as a common cause of iron deficiency anaemia, so it helps to start with healthy iron stores. A Ferritin test (£49) shows your stores and a Full Blood Count (£59) checks for anaemia. Once you are pregnant, the NHS checks iron at your booking appointment and again at around 28 weeks.

Thyroid function

Untreated thyroid problems can make pregnancy harder and, according to the NHS, an untreated underactive thyroid raises the risk of complications such as pre-eclampsia, premature birth and miscarriage. If you already take levothyroxine, tell your GP you are planning a pregnancy, as the dose usually needs to rise once you are pregnant. Our Thyroid test (£59) checks TSH, free T3, free T4 and thyroid antibodies. See our thyroid results guide.

Vitamin D

The NHS advises 10 micrograms of vitamin D a day in pregnancy, especially between October and March when sunlight is not strong enough, and all year for some people. A Vitamin D test (£59) shows whether your level is already low, which is more likely if you spend most of your time indoors, cover your skin outdoors or have dark skin.

HbA1c (blood sugar)

An HbA1c test (£59) shows your average blood sugar over recent months and can pick up diabetes or prediabetes before pregnancy. If you already have diabetes, NICE advises aiming for an HbA1c below 48 mmol/mol before conceiving, if this is possible without problem hypos, and strongly advises against pregnancy while HbA1c is above 86 mmol/mol. Speak to your diabetes team before you start trying.

STI screen: HIV, syphilis and hepatitis B

The NHS advises getting tested for sexually transmitted infections before trying for a baby if you or your partner might have one. HIV, syphilis and hepatitis B can all be passed to a baby, and each can be managed well when found early. You can test individually with our HIV Test (4th generation) (£49), Syphilis Blood Test (£49) and Hepatitis B Surface Antigen test (£49), or choose the STI Blood Screen (£99), which adds hepatitis C. Chlamydia can affect fertility and is tested with a urine sample or swab, see our Chlamydia and Gonorrhoea test (£59). Prefer to test at home? A home finger-prick kit is also available, ask us when you enquire.

AMH, only if relevant

AMH gives an estimate of how many eggs remain in the ovaries. It helps fertility clinics plan IVF and egg freezing, but NHS fertility guidance is clear that AMH is not related to the chance of conceiving naturally and should not be used to predict natural fertility. Consider the AMH (Ovarian Reserve) test (£99) only if you are thinking about egg freezing or IVF, or want to discuss timing with a specialist. Our guide to AMH levels explains the results.

What the NHS checks once you are pregnant

NHS antenatal screening is offered free in every pregnancy. It includes blood tests for HIV, syphilis and hepatitis B, ideally by 10 weeks, along with checks for anaemia. A private test before pregnancy does not replace these, but it lets you deal with anything unexpected before you conceive.

Which test should I book?

• A focused start: Fertility Panel, £159. Checks reproductive and thyroid hormones, folate, B12, vitamin D, iron studies with ferritin, a full blood count, HbA1c and liver and kidney markers in one sample.
• A broader picture: Fertility Panel with AMH, £219. The same panel with AMH added, for people who also want an estimate of egg reserve.
• The fullest view: Hormone and Thyroid Panel Plus, £249. A detailed hormone review with thyroid antibodies, AMH, prolactin, cortisol and DHEA-S, suited to irregular cycles or hormone questions.

None of these panels includes rubella immunity or an STI screen, so add those if you need them. Take a look at our women's health blood tests for related options.

What blood tests cannot tell you

Blood tests cannot tell you whether you will get pregnant or how long it will take, and normal results do not guarantee a problem-free pregnancy. AMH says nothing about egg quality. Male fertility depends mainly on a semen analysis, which is not a blood test. Lifestyle steps, such as stopping smoking, avoiding alcohol and keeping a healthy weight, matter as much as any test.

When to see a GP urgently

If you might be pregnant and have sudden, sharp, severe tummy pain, severe dizziness or fainting, or look very pale, call 999 or go to A&E, as these can be signs of an ectopic pregnancy. Contact your GP or NHS 111 if you might be pregnant and have pain on one side of your lower tummy, vaginal bleeding or brown discharge, or shoulder-tip pain.

See your GP before trying if you have a long-term condition such as diabetes, epilepsy, a thyroid condition, sickle cell disease or HIV. Do not stop any prescribed medicine until you have spoken to your GP or specialist. See a GP too if you have been trying to conceive for a year or more.

Frequently asked questions

What blood tests should I have before trying for a baby?

A sensible set is a full blood count, ferritin, folate, B12, thyroid function, vitamin D and HbA1c, plus rubella immunity and an STI screen if relevant. The Fertility Panel covers most of these in one visit.

Do I still need folic acid if my folate is normal?

Yes. The NHS advises 400 micrograms of folic acid daily for everyone trying to conceive, ideally from 3 months before pregnancy until 12 weeks, whatever your blood level.

Is the rubella test still done in pregnancy?

No. Routine rubella screening in pregnancy ended in England in 2016. The advice is to check your MMR status and be vaccinated before trying for a baby if needed.

Should my partner have blood tests too?

It can help. An STI screen is worthwhile for both partners if either of you might have an infection, and the NHS advises speaking to a GP if your partner has a long-term condition such as HIV or sickle cell disease.

Does a low AMH mean I cannot get pregnant?

No. AMH reflects egg numbers, not egg quality, and it does not predict the chance of natural conception. Discuss a low result with a practitioner or fertility specialist.

Pre-pregnancy blood testing in Chiswick

Omnia Lifestyle is at 8 to 9 Bedford Corner, The Avenue, Chiswick, London W4 1LZ, a short walk from Turnham Green station (District line; Piccadilly line trains stop there early morning and late evening only) and on the 94, E3 and 272 bus routes. Limited parking is available on request when you book. Every clinic test price includes your sample taken at the clinic, analysis at the Randox accredited laboratory, a review of your result with a practitioner and a GP feedback report on request. No GP referral is needed and most results are back within a few working days.

Book the Fertility Panel, add the Rubella Immunity test if you need it, or compare every blood test and price. For more reading, see our women's health blood tests and our guide to AMH levels.

This article is general information, not medical advice. Discuss your results with your GP or practitioner.